Recently, the Internet has been widely used and users utilize terminals connected to the Internet to obtain various types of information from the Internet. For example, when a user wishes to obtain information related to a certain keyword from the Internet, the user can obtain the information by using a search engine.
Further, even if the user does not know a specific keyword, the user can obtain diverse types of information such as news, topics, and recommended information selected by a service provider by accessing a portal site or a blog site managed by the service provider.
Many other services are provided through the Internet to the user who collects information. For example, “Shun word” by Nifty Corporation, [online], [Retrieved on Dec. 23, 2006], Website at <http://www.nifty.com/shun/> discloses a service to provide topical keywords to the user and prompt the user to search by the keywords. This service can provide the topical keywords to the user by ranking keywords searched for during a predetermined period and notifying the user of a result of the ranking.
Further, Japanese Laid-open Patent Publication No. 2006-31577 discloses a technique for setting an arrangement of information related to keywords searched for according to degrees of relationship between the keywords searched for and the information related to the keywords, thereby providing a more convenient information search to the user.
In the conventional techniques as described above, popular topics can be provided to the user; however, the reason why the provided topics are popular remains unknown.
Because information on the reason why the provided topic is popular is not provided to the user, the user has to perform search without knowing the reason. Then, the search hits a variety of information related to the topic (including information which is related to the topic though not related to the cause of its popularity). Thus, the user cannot utilize the topics conveniently in performing searches.
It is desirable to clarify the reason why the topics are popular in providing information on the topics to the user.